1). Field of the Invention
This invention relates to a needle assembly having a needle with a sharp needle distal end, and an elongate blunting device which can be used to prevent penetration trauma by the sharp needle distal end.
2). Discussion of Related Art
Needle assemblies are used for various medical purposes such as withdrawing fluids from a body of a person, in particular blood from a vein or an artery, providing fluids to a body of a person or for inserting an object such as a catheter into a vein or an artery.
A needle assembly includes a needle having a sharp needle distal end. The sharp needle distal end is used to pierce a body and is inserted into fluids in the body. Body fluids may include viruses which can transfer diseases to medical personnel. Once the needle is removed from the body, care should be taken that the sharp needle distal end does not penetrate into the body of any medical personnel.
An elongate blunting device may be used for preventing penetration trauma of such a sharp needle distal end. The elongate blunting device may be located within a needle cannula of the needle and be moveable by a shifting member from a retracted position wherein a blunting device distal end of the elongate blunting device is retracted into the needle cannula, to an extended position wherein the blunting device distal end extends out of the needle cannula, thereby preventing the sharp needle distal end from penetrating the body of any medical personnel.
A blood flow passage can be provided through the needle and a flash chamber may be in communication with the blood flow passage so that blood can flow from the blood flow passage into an internal volume of the flash chamber. The flash chamber is typically made of a material through which blood can be seen when located within the internal volume. Medical personnel can then see when the sharp needle distal end pierces a vein or artery because blood would then flow from the sharp needle distal end into the internal volume of the flash chamber. In order for blood to flow from the sharp needle distal end into the flash chamber it is required that air located within passages within the needle assembly be vented out of these passages. The present invention primarily concerns itself with venting of air from such passages.